A very specific kind of fog.


I need fog. But not the standard fogs that are in UE4. Neither Atmospheric Fog or Exponential Height Fog do what I want.

I want (almost) ‘real’ fog.

A fog that takes to color of the light I shine to it. And the fog should ideally receive shadows as well.

I’m aware that this could potentially be very heavy computational wise, but I’m not looking for perfect, just for good enough. The standard fogs just don’t cut it.

Do you guys have any idea how to make this? which direction to go?

Particles, heavy but they could work. Take a look at the effects level in the content example.

You could probably make a mix between the two - big soft sprites for the lighting, and exponential fog to take some of the load off.

You could also try a mix between the standard fog, a post volume and godrays. GPU particles are a way, but can become taxing on performance if you crank them up really high.

By the way, do you plan to “fill” the level or just have some kind of “bounding box” around your pawn to create the illusion?

are you wanting just the nearby fog to change like a small beam or the entire fog bank to change based on the color light applied to it?

If you look at what I did in Solus, I got something like that. When you enter caverns, which are pitch black, and you bring up a torch, fog lights up from the torch light.

And it is done with particles indeed, which is the only way to go about it right now. And it is indeed heavy. You need to use an as simple material as possible. To my test GPU particles did not help at all due to the very large size of the particles, so I am using normal CPU ones. And my particle is attached to the player to fog only appears around the player.

I believe it may be somewhere in this video: